/*
 * Copyright (c) 1997, 2003, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
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 *
 *
 *
 *
 *
 *
 *
 *
 */

package com.sun.java.swing.plaf.motif;

import javax.swing.*;
import java.awt.Rectangle;
import java.awt.Dimension;
import java.awt.Insets;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Component;
import java.awt.Point;
import javax.swing.plaf.*;
import java.io.Serializable;

/**
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases.  The current serialization support is appropriate
 * for short term storage or RMI between applications running the same
 * version of Swing.  A future release of Swing will provide support for
 * long term persistence.
 *
 * @author David Kloba
 */
public class MotifDesktopPaneUI extends javax.swing.plaf.basic.BasicDesktopPaneUI {

    /// DesktopPaneUI methods
    public static ComponentUI createUI(JComponent d) {
        return new MotifDesktopPaneUI();
    }

    public MotifDesktopPaneUI() {
    }

    protected void installDesktopManager() {
        desktopManager = desktop.getDesktopManager();
        if (desktopManager == null) {
            desktopManager = new MotifDesktopManager();
            desktop.setDesktopManager(desktopManager);
            ((MotifDesktopManager) desktopManager).adjustIcons(desktop);
        }
    }

    public Insets getInsets(JComponent c) {
        return new Insets(0, 0, 0, 0);
    }

    ////////////////////////////////////////////////////////////////////////////////////
    ///  DragPane class
    ////////////////////////////////////////////////////////////////////////////////////
    private class DragPane extends JComponent {
        public void paint(Graphics g) {
            g.setColor(Color.darkGray);
            g.drawRect(0, 0, getWidth() - 1, getHeight() - 1);
        }
    };

    ////////////////////////////////////////////////////////////////////////////////////
    ///  MotifDesktopManager class
    ////////////////////////////////////////////////////////////////////////////////////
    private class MotifDesktopManager extends DefaultDesktopManager implements Serializable, UIResource {
        JComponent dragPane;
        boolean usingDragPane = false;
        private transient JLayeredPane layeredPaneForDragPane;
        int iconWidth, iconHeight;

        // PENDING(klobad) this should be optimized
        public void setBoundsForFrame(JComponent f, int newX, int newY, int newWidth, int newHeight) {
            if (!usingDragPane) {
                boolean didResize;
                didResize = (f.getWidth() != newWidth || f.getHeight() != newHeight);
                Rectangle r = f.getBounds();
                f.setBounds(newX, newY, newWidth, newHeight);
                SwingUtilities.computeUnion(newX, newY, newWidth, newHeight, r);
                f.getParent().repaint(r.x, r.y, r.width, r.height);
                if (didResize) {
                    f.validate();
                }
            } else {
                Rectangle r = dragPane.getBounds();
                dragPane.setBounds(newX, newY, newWidth, newHeight);
                SwingUtilities.computeUnion(newX, newY, newWidth, newHeight, r);
                dragPane.getParent().repaint(r.x, r.y, r.width, r.height);
            }
        }

        public void beginDraggingFrame(JComponent f) {
            usingDragPane = false;
            if (f.getParent() instanceof JLayeredPane) {
                if (dragPane == null)
                    dragPane = new DragPane();
                layeredPaneForDragPane = (JLayeredPane) f.getParent();
                layeredPaneForDragPane.setLayer(dragPane, Integer.MAX_VALUE);
                dragPane.setBounds(f.getX(), f.getY(), f.getWidth(), f.getHeight());
                layeredPaneForDragPane.add(dragPane);
                usingDragPane = true;
            }
        }

        public void dragFrame(JComponent f, int newX, int newY) {
            setBoundsForFrame(f, newX, newY, f.getWidth(), f.getHeight());
        }

        public void endDraggingFrame(JComponent f) {
            if (usingDragPane) {
                layeredPaneForDragPane.remove(dragPane);
                usingDragPane = false;
                if (f instanceof JInternalFrame) {
                    setBoundsForFrame(f, dragPane.getX(), dragPane.getY(), dragPane.getWidth(), dragPane.getHeight());
                } else if (f instanceof JInternalFrame.JDesktopIcon) {
                    adjustBoundsForIcon((JInternalFrame.JDesktopIcon) f, dragPane.getX(), dragPane.getY());
                }
            }
        }

        public void beginResizingFrame(JComponent f, int direction) {
            usingDragPane = false;
            if (f.getParent() instanceof JLayeredPane) {
                if (dragPane == null)
                    dragPane = new DragPane();
                JLayeredPane p = (JLayeredPane) f.getParent();
                p.setLayer(dragPane, Integer.MAX_VALUE);
                dragPane.setBounds(f.getX(), f.getY(), f.getWidth(), f.getHeight());
                p.add(dragPane);
                usingDragPane = true;
            }
        }

        public void resizeFrame(JComponent f, int newX, int newY, int newWidth, int newHeight) {
            setBoundsForFrame(f, newX, newY, newWidth, newHeight);
        }

        public void endResizingFrame(JComponent f) {
            if (usingDragPane) {
                JLayeredPane p = (JLayeredPane) f.getParent();
                p.remove(dragPane);
                usingDragPane = false;
                setBoundsForFrame(f, dragPane.getX(), dragPane.getY(), dragPane.getWidth(), dragPane.getHeight());
            }
        }

        public void iconifyFrame(JInternalFrame f) {
            JInternalFrame.JDesktopIcon icon = f.getDesktopIcon();
            Point p = icon.getLocation();
            adjustBoundsForIcon(icon, p.x, p.y);
            super.iconifyFrame(f);
        }

        /**
         * Change positions of icons in the desktop pane so that
         * they do not overlap
         */
        protected void adjustIcons(JDesktopPane desktop) {
            // We need to know Motif icon size
            JInternalFrame.JDesktopIcon icon = new JInternalFrame.JDesktopIcon(new JInternalFrame());
            Dimension iconSize = icon.getPreferredSize();
            iconWidth = iconSize.width;
            iconHeight = iconSize.height;

            JInternalFrame[] frames = desktop.getAllFrames();
            for (int i = 0; i < frames.length; i++) {
                icon = frames[i].getDesktopIcon();
                Point ip = icon.getLocation();
                adjustBoundsForIcon(icon, ip.x, ip.y);
            }
        }

        /**
         * Change positions of icon so that it doesn't overlap
         * other icons.
         */
        protected void adjustBoundsForIcon(JInternalFrame.JDesktopIcon icon, int x, int y) {
            JDesktopPane c = icon.getDesktopPane();

            int maxy = c.getHeight();
            int w = iconWidth;
            int h = iconHeight;
            c.repaint(x, y, w, h);
            x = x < 0 ? 0 : x;
            y = y < 0 ? 0 : y;

            /* Fix for disappearing icons. If the y value is maxy then this
             * algorithm would place the icon in a non-displayed cell.  Never
             * to be ssen again.*/
            y = y >= maxy ? (maxy - 1) : y;

            /* Compute the offset for the cell we are trying to go in. */
            int lx = (x / w) * w;
            int ygap = maxy % h;
            int ly = ((y - ygap) / h) * h + ygap;

            /* How far are we into the cell we dropped the icon in. */
            int dx = x - lx;
            int dy = y - ly;

            /* Set coordinates for the icon. */
            x = dx < w / 2 ? lx : lx + w;
            y = dy < h / 2 ? ly : ((ly + h) < maxy ? ly + h : ly);

            while (getIconAt(c, icon, x, y) != null) {
                x += w;
            }

            /* Cancel the move if the x value was moved off screen. */
            if (x > c.getWidth()) {
                return;
            }
            if (icon.getParent() != null) {
                setBoundsForFrame(icon, x, y, w, h);
            } else {
                icon.setLocation(x, y);
            }
        }

        protected JInternalFrame.JDesktopIcon getIconAt(JDesktopPane desktop, JInternalFrame.JDesktopIcon icon, int x, int y) {

            JInternalFrame.JDesktopIcon currentIcon = null;
            Component[] components = desktop.getComponents();

            for (int i = 0; i < components.length; i++) {
                Component comp = components[i];
                if (comp instanceof JInternalFrame.JDesktopIcon && comp != icon) {

                    Point p = comp.getLocation();
                    if (p.x == x && p.y == y) {
                        return (JInternalFrame.JDesktopIcon) comp;
                    }
                }
            }
            return null;
        }
    }; /// END of MotifDesktopManager
}
